File type signifiers and format identifiers

Indicated in file wrapper and relates to "brands" defined in ISO_BMFF. Wrapping MPEG-4_V bitstreams in MP4_FF_1 would occasion the use of mp41; in MP4_FF_2, use mp42. See Part 15 of the standard, pp. 2-9, 13.

Notes

General

Fernando Pereira and Touradj Ebrahimi report on page 598 of The MPEG-4 Book that the Advanced Simple Profile "represents a compromise between the desire to support interlace at higher bit rates and the desire to keep the number of profiles manageable. . . . It is likely that another level, termed 3b, will be added . . . [which] will allow higher bit rates without having to support interlaced coding."